In-Hospital Aspirin Dose as a Risk Factor for Hemorrhagic Transformation in Patients Not Treated With Thrombolysis

BACKGROUND: Aspirin is widely used as secondary prophylaxis for acute ischemic stroke. However, its influence on the risk of spontaneous hemorrhagic transformation (HT) is still unclear. Predictive scores of HT have been proposed. We hypothesized that an increased aspirin dose might be harmful in patients at a high risk of HT. This study aimed to analyze the relationship between in-hospital daily aspirin dose (IAD) and HT in patients with acute ischemic stroke. METHODS: We conducted a retrospective cohort study of patients admitted to our comprehensive stroke center between 2015 and 2017. The attending team defined IAD. All included patients underwent either computed tomography or magnetic resonance imaging within 7 days of admission. The risk of HT was assessed using the predictive score of HT in patients not undergoing reperfusion therapies. Regression models were used to evaluate the correlations between HT and IAD. RESULTS: A total of 986 patients were included in the final analysis. The prevalence of HT was 19.2%, and parenchymatous hematomas type-2 (PH-2) represented 10% (n=19) of these cases. IAD was not associated with HT ( P =0.09) or PH-2 ( P =0.06) among all patients. However, in patients at a higher risk for HT (patients not undergoing reperfusion therapies ≥3), IAD was associated with PH-2 (odds ratio 1.01,95% CI 1.001-1.023, P =0.03) in an adjusted analysis. Taking 200 versus 300 mg aspirin was protective against PH-2 (odds ratio 0.102, 95% CI 0.018-0.563, P =0.009). CONCLUSION: An increased in-hospital aspirin dose is associated with intracerebral hematoma in patients at a high risk of HT. Stratifying the risk of HT may lead to individualized daily aspirin dose choices. However, clinical trials on this topic are required.